12.04 server network install won't reboot when finished

[Yazz D. Atlas]

I can not get the 12.04 network install to finish correctly. It keeps looping over and over at the last part where it should be rebooting the new system. It never ends. If I have a preseed/late_command I can see that the command completes and the /target is unmounted. Then the loop starts but fails since /target is not mounted.

This is preventing installing a larger number of machines using iPXE at the moment.

Screen capture of what happens
https://vimeo.com/44347114

My preseed.cfg (private data remove)
http://pastebin.com/gDV2vdcq

The iPXE script
http://pastebin.com/q9c44Wgt